A coorpobationi



April 29, 1924. 1,491,897

J. M. BLAKE LOWER DISK FOR ROTARY CRUSHERS Filed Jan. 29. 1921' i l's'l'l'l'l'llmlll ,f v I atented Apr. 29, 1912 4.

U NlTED. STATES I i v 1,491,897 PATENT. OFFICE.

M T/BLAKE, OF CHICAGO HEIGHTS, ILLINOIS, ASSIG-NOR TO AMERICAN MAN- I GAIN ESE STEEL COMPANY, OF CHICAGO, ILLINOIS, A- CORPORATION OF MAINE.

LOWER nrsx son ROTARY cnusnims.

' Application filed January 29, 1921. Serial No. 440,846.

To all whom it may concern:

Be. it known that I, JUDSON M. BLAKE, a citizen of the'United States, residing at Chicago Heights, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Lower Disks for Rotary Crushers, of which the following is a specification.

My invention relates to rotary crushers i0 and particularly to a lower plate or disk for rotary crushers. It is designed primarily for. use in crushers of the Symons type, in which there is a gyratory and oscillatory movement of one disk relatively. to the other disk, but it is applicable also to disk crushers operating by mere relative rotation between the disks.

For the fine reduction ofore and the like, the Symons type of crusher employs two horizontally disposed disks, of which the lower one is substantially flat and the upper one has a conical central portion into which the ore is fed, surrounded by a marginal flange substantially parallel with the lower disk and coacting therewith to crush the ma terial. For fine reduction the minimum opening between the upper and lower crushing faces of a machine of the kind referred to will be about of an inch, and substantially all the crushing of the ore and the principal wear upon the disks take place near the peripheries of the parallel faces of the. disks and' -over an area extending in- I wardly therefrom approximately 6 inches. As crushing continues, the worn surfaces of the disks recede, and this necessitates adjustment' to maintain the opening of of an'inch between the crushing areas. After I continued service the wear is so great that 40 a shoulder or bell is formed on the upper surface of the lower disk, which comes so close to the upper disk as to prevent the feed of ore from the central space provided by the cone of the upper disk to the marginal 'nding surfaces. When this condition has een reached, replacement of the lower. disk has heretofore been necessary for fine crushaxial lane of the disk so that, in coaction with t e flat under disk, it will crush thematerial and prepare it for admission to the line reduction area between the parallel faces.

But this curved area soon reduces and eventually disappears under wear of the upper crushing surface.

My invention is directed to a lower disk so formed .as to prevent the formation of the- In carryin out my invention, I form inv the portion 0 the upper surface of the lower disk, over an area inside of the straight or parallel crushing area, a feeding recess or concavity that merges with the straight crushing area in an annulus that is radially beyond the annulus of the shoulder formed by the mer er between the conical and straight sur aces of the upper disk. This recess or concavity is thereby adapted to serve the urpose of passing the material beneath said shoulder. I also extend the concavity or recess outward beyond the annular locus of the shoulder or bell that develops from the coaction of a Symons upper disk with a continuously flat lower disk, and thereby maintain an unobstructed feed from the inner recess of the lower disk to the outer crushing face thereof as the latter face wears away.

The various novel features of my invention will be apparent from the following description and drawings and will be particularly pointed out in the appended claims.

In the accompanying drawings:

Figure 1 shows a vertical sectional view of a lower disk constructed in accordance with my invention and a portion of an upper disk; and

Figure 2 is a top plan view of the lower disk of Figure 1.

The upper disk B is formed with a flat marginal portion 5 extending outwardly from the conical portion 5 The lower disk A is provided with a flat marginal portion 6, and the usual central shaft opening 7. Formed in the upper surface of the lower disk A is an outwardly tapering annular recess or depression 8, the outer margin 9 of which is arranged outwardly beyond the shoulder 10 formed on the upper disk, by the merger of the inner face of the conical portion 5 and the lower surface of-the straight marginal portion 5 thereof. The inner margin 11 of the recess 8 rises to a higher level than the recess and termi nates short of the shoulder 12 surrounding 10 the central opening 7 in the disk. The depth of the depression 8 is made to suit the con dition of service, such as size and speed of the mill and class and quality of ore to be crushed. In service the upwardly presented annular grinding surface 13 of the lower disk A may wear a distance equal to the depth of the pocket 8, or until the surface 13 is flush with the bottom of the recess 8, before any barrier to the feed will develop. The ore which is fed through the usual hopper into the conical portion of the upper disk B rests on the lower disk A and is driven outwardly by centrifugal action be tween the marginal portions of the disks where the ore is crushed or to within reach of the overhanging portion 10 which assists in rolling the pieces into the crushing space. The crushing opening may be varied to suit conditions. The recess 8 merges very gradually with the surface 13, and will be worn down to some extent and its obliteration defig to of an inch high, which will not prelayed by the grinding efiect of the overhang 10. Continued use of the lower disk will increase the wear on the surface 13 thereof and radually this surface will be worn below t e bottom of the recess 8, however, the

depth of the recess 8 is such as to prevent the formation of a bell beneath the shoulder 10 in disk B that would prevent the discharge of ore to the marginal portions of the disks. Wear of the lower disk may continue until the marginal portions are so thin as to call for replacement.

By forming an annular depression in the upper surface of the lower disk with the outer periphery of the depression starting a slight distance beyond the juncture of the conical wall of the upper disk with the lower, flat surface thereof, and with the inner periphery near the central portion of the disk, or surrounding the usual central opening therethrough. An ore bed is maintained that forms the surface over which the material travels to the grinding faces and greatly relieves the lower disk from friction. With this, construction it is possible to prolong the life of the lower disk considerably as the depth of the pocket or recess is made proportional to'the thickness of the'disk so that as the marginal portion of the disk becomes worn a shoulder or bell will not be formed on the lower disk of suflicient height to stop the flow of the ore until such time that the disk is worn so thin-as to be discarded.

By way of example let it beassumed that the lower disk is 48 inches in diameter and about 2 inches in thickness, with a flat disk of this size the bell or shoulder would start to form after the marginal portion of the lower disk had worn about of an inch and this shoulder or bell would extend around on the ldwer disk in contact with the shoulder in the lpper disk so that the shoulder on the 10x er disk would be from a quarter of an ich to .1 6 of an inch higher than the worn} portion of the lower disk. When the lower disk has been worn from 1 to 1% inches'y'the bell? would be so high as'to preclud the passage of ore to the grinding portions of the disks and necessitate replacement of the lower disk. With the lower dif'sk constructed in accordance with my invention 48 inches in diameter and 2 inches thick the recessor pocket would be formed /about *3 to g of an inch deep starting at /about 6 inches from the outside edge of the disk and terminating near the central szzaft opening in the disk. Consequently, iththe marginal or grinding portions of the lower disk worn about of an inch the surface of the disk will be perfectly flat. With the marginal portion worn a of an inch a bell will be formed of only of an inch and when the plate has worn to 1 inch or 1% inches the bell will be only vent the passage of ore to the grinding portions of the disk. Before the bell is deep enough to interfere with the passage of the ore the grinding portions of the lower disk may be worn another 5 of an inch or about 1% inches total wear before the bell will interfere with the passage of ore to the grinding portions. .It will thus be seen that the full effectiveness of the lower disk is attained as the disk when worn to only half an inch in thickness is ready to be replaced by a new one.

'lVhile I have described more or less precisely the details of coustruc'tion of my invention, I do not wish. to be understood as limiting myself thereto, as I contemplate changes in form and the proportion of parts and substitution of equivalents as circumstances may suggest or render expedient, without departing from the spirit of my invention.

I claim:

1. A disk crusher comprising upper and lower disks constructed with substantially horizontal opposed peripheral crushing faces; the upper disk having a feeding concavity that develops a shoulder at the inner margin of its said peripheral crushing face;

and the lower disk being constructed with an upwardly presented annular recess that exlower disks constructed with substantially extends radially outward beyond said shoulhorizontel opposed peripheral crushing der and tapers upwardly tothe level of the faces;,the upper disk having a feeding conperipheral crushing face of said lower 1 cavity that develops a shoulder at the inner disk.

5 margin of its said peripheral crushing face; Signed at Chicago Heights, 111., this 20th and the lower disk being constructed with day of January, 1921. an upwardly presented annular recess that JUDSON M. BLAKE. 

